AssParser

ass_parser is a crate to parse .ass (Advanced SubStation Alpha) files. which is a subtitle file for creating and displaying subtitles in video files. It is widely used due to it's complex text formatting, positioning and styling. The Advanced SubStation Alpha is a successor to the SubStation Alpha .ssa file.

Installation

Add ass_parser as a dependency to your cargo.toml:

cargo add ass_parser

Introduction

AssParser is based on the principle of easy to read write and modify .ass files. This is the first version of ass_parserand now currently only have the features to modify .ass file.

Example

Creating a simple Advanced SubStation Alpha (.ass) file with default values

use ass_parser::{self, AssFile, ScriptInfo, V4Format, Events, AssFileOptions};
use hex_color::HexColor;

fn main() {
    let mut ass_file = AssFile::new();
    let hexcolor = AssFileOptions::get_ass_color(HexColor::YELLOW);

    ass_file.components.script
        .set_script(ScriptInfo::default());

    ass_file.components.v4
        .set_v4(V4Format::default())
        .set_primarycolour(hexcolor);

    ass_file.components.events
        .set_events(Events::default());

    AssFile::save_file(&ass_file, "new_subtitles.ass")

}

Here we create an .ass file with default values and When you open the .ass file you can see the following content.

ScriptType: v4.00+
PlayResX: 384
PlayResY: 288
ScaledBorderAndShadow: yes
YCbCr Matrix: None


[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,16,&H00ff,&Hffffff,&H0,&H0,0,0,0,0,100,100,0,0,1,1,0,2,10,10,10,1


[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:01.00,Default,,0,0,0,,Hello Friend

You can burn this subtitle file to a video or use any video player to select a video file along with this subtitle file.

Using FFmpeg to burn the video with the subtitles file.

You will first have to download and install FFmpeg on your system to try this. Once you have downloaded you can use the following command to burn the video file video.avi and the generated subtitle file new_subtitles.ass to a single output video file output.avi

ffmpeg -i video.avi -vf "ass=new_subtitles.ass" output.avi